The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
Air-carbon arc systems and processes may be used in a wide variety of applications, such as metal fabrication and casting finishing, chemical and petroleum technology, construction, mining, general repair, and maintenance. With respect to metal fabrication and casting finishing, air-carbon arc metal removing systems and processes may be used to gouge, groove, cut, or flush metal from a surface. Nearly all metals may be fabricated, including, but not limited to: carbon steel, stainless steel and other ferrous alloys; gray, malleable and ductile iron; aluminum; nickel and copper alloys and other nonferrous metals.
It may be desirable to use air-carbon arc metal removing systems or processes to modify a working piece such as to have a generally flat, flush, smooth, and/or otherwise constant surface. However, if the work piece surface includes irregularities, then it may be difficult to create a generally flat, flush, smooth, and/or otherwise constant surface through the use of air-carbon arc systems processes.
It may be desirable to remove and/or reapply hardfaced material from an object. “Hardfacing” is a technique which involves applying a layer of hard material to a substrate for the purpose of increasing the wear and corrosion resistance of the substrate. The layer of hard material may be applied to the object by welding or thermal spraying. Hardfacing by arc welding may be used as a surfacing operation to extend the service life of industrial components, pre-emptively on new components, or as part of a maintenance program. Hardfacing may result in significant savings in machine down time and production costs; as a result this process has been adopted across many industries such as steel, cement, mining, petrochemical, power, sugar cane and food.
Steel mill rolls or shafts are often hardfaced. For example, rolls and shafts are commonly modified to have a series of concentric hardfaced circles adjacent to each other and evenly-spaced along all or a portion of the length of the roll or shaft. As another example, rolls or shafts may be modified to have a series of square-shaped hardfaced surfaces adjacent to each other and evenly-spaced along all or a portion of the length of the roll or shaft. Hardfaced steel mill rolls may be used in a variety of applications, such as a crushing roller for a paper mill.
Despite the advantages of hardfacing, hardfaced material may be subject to wear before the non-hardfaced material of a component. This may be due to many factors such as the brittleness or other properties of the hardfaced material or the fact that hardfaced portions of a component are often the working surfaces of the component and are therefore subject to disproportionate stresses and forces while the component is in operation. As a result of these and other factors and varying operating conditions, hardfaced materials may not wear evenly and may include irregular surfaces.
It is therefore desirous to provide an air-carbon arc system and apparatus for detecting and/or reducing irregularities in a work piece surface and a method of using the same.